In the face of sharply escalating demands, developing countries face severe shortages of capital to invest in the necessary increases in generating capacity. Meanwhile, a substantial and cheaper untapped resource to meet the increasing demand already exists in terms of the large improvements possible in efficiencies of existing and future end uses of electricity in these countries. This paper illustrates with analysis two of the promising efficient end use technologies for developing countries: compact fluorescent lamps, and advanced windows for air conditioned buildings.